反应详情

To a solution of 2,4-dichloropyridine (2 g, 13.51 mmol) in tetrahydrofuran (20 mL) at −78° C., was added LDA, 2M in THF/heptane/ethylbenzene (8.11 mL, 16.22 mmol) and the solution was stirred for 30 min. DMF (10.46 mL, 135 mmol) was added and the solution was stirred for 1 h and then warmed RT. The reaction mixture was quenched with saturated NH4Cl solution and diluted with ethyl acetate (50 mL). The organic layer was washed with saturated NaHCO3 (2×10 mL), water (20 mL), dried over Na2SO4 and concentrated under reduced pressure to afford 2,4-dichloronicotinaldehyde (2 g, 11.36 mmol, 84% yield) as a yellow solid. 1H NMR (400 MHz, CDCl3) δ 10.49 (s, 1H),), 8.44 (d, J=5.4 Hz, 1H), 7.43 (d, J=5.4 Hz, 1H).

1. stirringthe solution was stirred for 1 h
2. customThe reaction mixture was quenched with saturated NH4Cl solution
3. additiondiluted with ethyl acetate (50 mL)
4. washThe organic layer was washed with saturated NaHCO3 (2×10 mL), water (20 mL)
5. dry with materialdried over Na2SO4
6. concentrationconcentrated under reduced pressure